The SGT offer a range of glasses and raw materials intended for the verification of analytical methods, such as those used by the participating laboratories, for the calibration of analytical instruments, for establishing values for secondary reference materials, for the validation of analytical procedures and for training purposes. These reference materials have been generated by the Analysis and Properties Technical Committee now working in collaboration with the Bureau of Analysed Samples Ltd www.basrid.co.uk .

Certified Reference Materials (CRMs) produced from November 2000 onwards demonstrate traceability in accordance with the principles of ISO Guides 30 – 35 and the International Vocabulary of Basic and General Terms in Metrology. Our commitment to continuous improvement is further demonstrated with CRMs issued from 2007 onwards being produced under ISO Guide 34 accreditation.

Characterisation of CRMs has been achieved by inter-laboratory study, each laboratory using method(s) of their choice, details of which are given in the certificate accompanying the appropriate CRM. Most methods used were either international or national standard methods or methods which are technically equivalent. All laboratories used either stoichiometric analytical techniques or methods which were calibrated predominantly against pure metals or stoichiometric compounds.

Some of the participating laboratories were accredited to ISO/IEC 17025 at the time of the analysis, although not necessarily for all of the constituents determined. It has been established statistically that there is no difference between the results of the accredited and the non-accredited laboratories.

The SGT wish to thank all participating laboratories for their assistance in the certification process. Our network, as from November 2007, includes laboratories from Great Britain, the Czech Republic, Greece, Germany, Sweden, Italy, Japan, Turkey and the United States of America although the actual number of participating analysts vary with each candidate material.

For a full listing of analytes and more details see the pdf links to the individual CRM certificates.

The SGT is proud to offer the following CRMs prepared in collaboration with the Bureau of Analysed Samples Ltd

SGT Dolomite (BCS-CRM 512)SGT Limestone (BCS-CRM 513)

SGT Feldspar (BCS-CRM 376/1) SGT Soda-Ash (BCS-CRM 526)

Please note that this Potash Feldspar has been produced under ISO Guide 34 accreditation.

These materials are available in bottles of 100g of finely divided material for chemical analysis passing a nominal 250 micron aperture. The cost is £70.00 plus postage to non members and at the discounted rate of £50.00 plus postage for SGT members.

The CRMs will remain stable provided that the bottle remains sealed and is stored in a dry atmosphere. When the bottle has been opened the lid should be secured immediately after use. In order to ensure that a fully representative sample is taken, users should take a minimum sub-sample size of 1.0 g. Users of this material should be aware that the use of a smaller sub-sample size will invalidate the certified values and the associated 95% confidence limits. Provided that the material is stored in a suitable environment there will be no contribution to the uncertainty from the long term stability of this CRM.